Drug delivery system with magnetic ring and sensors arranged in a ring pattern

Abstract

A drug delivery system comprises an indicator element and a sensor system. The indicator element is arranged to rotate relative to a reference component and corresponding to a reference axis and comprises a magnetic ring. The sensor system comprises a plurality of magnetometers arranged non-rotational relative to the reference component and adapted to determine continuous magnetic field values from the plurality of dipole magnets, as well as processor means configured to determine on the basis of measured values from the plurality of magnetometers a rotational position and / or a rotational movement of the indicator element.

Description

REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of International Application PCT / EP2018 / 083324 (published as WO 2019 / 110494), filed Dec. 3, 2018, which claimed priority of European Patent Applications 17205062.7, filed Dec. 4, 2017; and 17205063.5, filed Dec. 4, 2017; the contents of all above-named applications are incorporated herein by reference.[0002]The present invention generally relates to medical systems and devices for which the generation, collecting and storing of data are relevant. In specific embodiments the invention relates to systems and devices for capturing and organizing drug delivery dose data in a reliable and user-friendly way.BACKGROUND OF THE INVENTION[0003]In the disclosure of the present invention reference is mostly made to drug delivery devices comprising a threaded piston rod driven by a rotating drive member, such devices being used e.g. in the treatment of diabetes by delivery of insulin, however, this is only an exemplary use...

AI Technical Summary

Benefits of technology

[0015]By this arrangement a drug delivery system is provided in which external as well as internal magnetic disturbances can be cancelled out to a large extent in a cost-effective and energy-effective way by signal processing algorithms based on input from the rotating plurality of dipole magnets.

[0020]At least a portion of the magnetometers may be adapted to measure a magnetic field in the axial as well as a tangential direction. Alternatively, the magnetometers may be in the form of 3-axis “compass” sensors adapted to measure a magnetic field in the axial, tangential as well as radial direction. The processor means may be configured to determine a rotational position and / or a rotational movement of the indicator element on the basis of measured values from the plurality of magnetometers in the axial and in tangential directions only, i.e. the ability to measure a magnetic field in the radial direction is not utilized, this lowering energy consumption and reducing the signal processing requirements. This concept is based on the realization that in a typical drug delivery device the largest degree of slack for a rotating indicator member is based on tolerances in the radial direction.

[0031]By this arrangement a sensor assembly is provided with a shield which does not only shield the sensor system from external magnetic fields, but also helps divert any unintended internal magnetic field introduced by the magnetisable metal component when magnetized. By reducing the strength of the disturbing field from the metal component it may enable the use of fewer sensors and thus lower signal processing requirements to obtain required accuracy and redundancy, and thereby reduce both costs and power consumption.

[0032]The circumscribing diameter for the magnetisable metal component may be larger than the circumscribing diameter for the magnetic indicator element. In this way the shield will to a higher degree be able to absorb magnetic lines from a magnetized member than the magnetic indicator element.

Problems solved by technology

However, such logs are normally kept in handwritten notebooks, and the logged information may not be easily uploaded to a computer for data processing.

A missing or erroneous record in the log results in a misleading picture of the injection history and thus a misleading basis for the medical personnel's decision making with respect to future medication.

The latter devices are to be discarded after being emptied and so inexpensive that it is not cost-effective to build-in electronic data acquisition functionality in the device it-self.

Images